On Fri, Jan 29, 2021 at 10:09:03AM +0000, Tian, Kevin wrote:

quoted

SVA is not doom to work with IO page fault only. If we have SVA+pin,
we would get both sharing address and stable I/O latency.

Isn't it like a traditional MAP_DMA API (imply pinning) plus specifying 
cpu_va of the memory pool as the iova? 

I think their issue is the HW can't do the cpu_va trick without also
involving the system IOMMU in a SVA mode

It really is something that belongs under some general /dev/sva as we
talked on the vfio thread

Jason